The Roosters continued their impressive start to the year on Saturday night, upsetting grand finalists the Warriors 26-8 in a scrappy affair at the Sydney Football Stadium.

The victory moves the Roosters into the top eight, while Brian McClennan's Warriors fell to their third loss of the year after an uncharacteristically lackadaisical effort.

The Roosters led from start to finish, scoring in the fifth minute through New Zealand international Shaun Kenny-Dowall and regularly extending that lead throughout the clash as the Warriors struggled to get in the game.

Hooker Anthony Mitchell, given a starting spot by coach Brian Smith in a heavily reshuffled line-up, channelled his inner-Billy Slater with an excellent try late in the first half.

Mitchell pounced on a grubber from second-rower Brad Takairangi, grounding the ball centimetres inside the deadball line for the night's most unlikely try.

Roosters centre Mitchell Aubusson also crossed in the first half, palming off opposition half-back Shaun Johnson on his way to the try-line as the home side dominated field position and possession, as well as the scoreboard.

A late try to Jerome Ropati for the Warriors reduced the lead to 12 before the half-time break.

But there simply was not enough in the tank for the Warriors in the second half as the Roosters' big men muscled up against their more-fancied opposing pack.

Only a 40-metre screamer from Warriors fill-in full-back Glen Fisiiahi gave the impression the Kiwis might mount a fightback, but errors continued to haunt them, as Braith Anasta kicked two penalty goals to keep the scoreboard ticking over.

Anasta was well and truly on his game despite signing a two-year deal with Wests Tigers during the week, leading the Roosters around the park in a composed display, while fellow veteran Anthony Minichiello, who scored in the final minute of the game, was outstanding at the back.

Roosters enforcer Jared Waerea-Hargreaves was among the best on the field but may find himself in trouble with the match review panel after he was put on report in the 55th minute for a high shot on Ukuma Ta'ai.

McClennan lamented the Warriors' slow start and said his side was always likely to struggle after giving the Roosters 60 per cent of possession in the first half, causing his side to make an extra 56 tackles before the break.

"We were very shaky at the start and coughed up a lot of ball and put loads of pressure on ourself," he said.

"We hold our hands up, we were poor in those standards.

"If our boys had that amount of ball, I'm sure we would've got the money."

Roosters mentor Brian Smith agreed that the opening 20 minutes dictated the win, but was critical of the decision to put Waerea-Hargreaves on report, suggesting Ta'ai had feigned injury to win the penalty.

"A high shot? I thought (it) was what you'd call powderpuff," Smith said.

"I was embarrassed for the rules in our game did what that young man had to do to feign ... it appeared to me he wasn't really badly injured ... but they get two interchanges out of it because the refs put him on report.

"It's a loophole in the system, but I'm not blaming anybody for it. Our guys probably would've done the same thing."